A hydraulic oil cylinder is widely used in different industries, especially in a lifting mechanism of a forklift, due to a working stability thereof. There are mainly two kinds of hydraulic oil cylinder used in a forklift: a piston cylinder and a plunger cylinder. In order to avoid the influence caused by mechanical collisions of a piston, a buffering component needs to be fixed in both of the piston cylinder and the plunger cylinder. Currently, a technology of a low region (i.e. a region adjacent to the bottom end of the cylinder body) buffering is maturely used in the piston cylinder and the plunger cylinder of forklift and has an excellent buffering effect.
However, because a working frequency in the low region is greatly higher than that in a high region (i.e. a region adjacent to the top end of the cylinder body), a significance of the high region buffering is usually ignored in application of forklift. In fact, mechanical collisions occurred in the high region is also very dangerous. Therefore, in order to improve a reliability and security performance of the forklift, it is necessary to add a high region buffering component in the piston cylinder or the plunger cylinder.